Broadband remote access server (BRAS) system-based packet encapsulation

ABSTRACT

A BRAS system-based packet encapsulation method includes: obtaining user access information when receiving a user access protocol packet, performing VXLAN GPE encapsulation on the user access protocol packet based on the user access information, the encapsulation structure includes a user information header that is used to store the user access information, a quantity of bytes occupied by the user information header is less than or equal to 12. In this application, the foregoing encapsulation structure is used to encapsulate a packet.

CROSS-REFERENCE TO RELATED APPLICATIONS

This is a continuation of Int'l Patent App. No. PCT/CN2018/084945 filedon Apr. 27, 2018, which claims priority to Chinese Patent App. No.201710459385.1 filed on Jun. 16, 2017, which are incorporated byreference.

TECHNICAL FIELD

This disclosure relates to the field of communications technologies, andin particular, to a broadband remote access server (BRAS) system-basedpacket encapsulation method and apparatus.

BACKGROUND

With a dramatic increase in a quantity of household broadband users andrapid development of new services such as an ultra-high definitiontelevision (e.g., 4K) and virtual reality (VR), a conventional BRASsystem faces huge challenges such as low resource utilization andcomplex management and maintenance. Therefore, communications operatorsproposed a BRAS system that separates a forwarding function from acontrol function. That is, user management and control functionsimplemented by using a plurality of BRAS devices in the conventionalBRAS system are separated from a forwarding plane function andcentralized together, and are implemented by a dedicated server orserver cluster. The dedicated server or server cluster is referred to asa BRAS control plane (BRAS-CP). However, a conventional control planefunction such as routing or multicast and a forwarding plane functionsuch as traffic forwarding or traffic statistics collection that are ofthe conventional BRAS system are still implemented by the plurality ofBRAS devices. In this case, the plurality of BRAS devices form a BRASuser plane (BRAS-UP). In a BRAS system in which the forwarding functionis separated from the control function, a user access protocol packet istransmitted between the BRAS-CP and the BRAS-UP transmit over a virtualextensible local area network (VXLAN). When a user accesses a network,the BRAS-CP needs to obtain user access information from the user accessprotocol packet to attempt to authenticate a user access location.Therefore, when the BRAS-UP receives the user access protocol packet andencapsulates the user access protocol packet through VXLANencapsulation, the BRAS-UP needs to add the user access information tothe to-be-encapsulated packet.

SUMMARY

In standard VXLAN encapsulation, there is no suitable location to whichthe user access information is added. BRAS-UP may encapsulate the useraccess protocol packet in two manners. In a first manner, the useraccess protocol packet is encapsulated by using a standard VXLAN. Beforethe encapsulation, the BRAS-UP may add a user information header betweena VXLAN header and the user access protocol packet, and the userinformation header is used to store the user access information. Thenthe BRAS-UP encapsulates the added user information header and the useraccess protocol packet according to the standard VXLAN encapsulation toobtain an encapsulated packet. In a second manner, the user accessprotocol packet can be encapsulated by using a VXLAN generic protocolextension (VXLAN GPE) mechanism. The BRAS-UP may set a next protocolfield in a VXLAN GPE header to a first value, the next protocol field isalso referred to as an encapsulation protocol field, the first value isused to indicate that an adjacent field after the VXLAN GPE header is anetwork service header (NSH), and a context header of the NSH may storethe user access information. For example, the first value may be 4.

However, when the user access protocol packet is encapsulated in thefirst manner, the user information header is added. Therefore, it isequivalent to modifying the standard VXLAN encapsulation. Consequently,the encapsulated packet lacks compatibility. When the user accessprotocol packet is encapsulated in the second manner, the context headerof the NSH is 4-byte aligned and variable in length. In addition, theNSH occupies many bytes, and another header occupies bytes duringencapsulation by using the VXLAN GPE mechanism. Consequently, anencapsulated packet header occupies more bytes. In comparison with theuser access protocol packet that occupies fewer bytes, higherencapsulation overheads are caused.

This disclosure provides a BRAS system-based packet encapsulation methodand apparatus to resolve problems of incompatibility of an encapsulatedpacket caused by using VXLAN encapsulation and excessively highencapsulation overheads when VXLAN GPE encapsulation is used in theabove two manners. The technical solutions are as follows:

According to a first aspect, a BRAS system-based packet encapsulationmethod is provided, and the method includes: obtaining user accessinformation corresponding to a user access protocol packet whenreceiving the user access protocol packet; and performing virtualextensible local area network generic protocol extension VXLAN GPEencapsulation on the user access protocol packet based on the useraccess information, where a VXLAN GPE encapsulation structure includes aVXLAN GPE header, a value of an encapsulation protocol field of theVXLAN GPE header is a preset value, the preset value is used to indicatethat the VXLAN GPE encapsulation structure includes a user informationheader, the user information header is used to store the user accessinformation, the user information header is located after the VXLAN GPEheader and is adjacent to the VXLAN GPE header, and a quantity of bytesoccupied by the user information header is less than or equal to 12.

It should be noted that because the VXLAN GPE encapsulation structurehas relatively good backward compatibility, the VXLAN GPE encapsulationperformed on the user access protocol packet based on the user accessinformation resolves a problem of incompatibility caused by modifyingstandard VXLAN encapsulation when the user access information is carriedduring VXLAN encapsulation. In addition, in an embodiment of the presentdisclosure, after the value of the encapsulation protocol field of theVXLAN GPE header in the VXLAN GPE encapsulation structure is set to thepreset value, a part that is located after the VXLAN GPE header in theVXLAN GPE encapsulation structure and is adjacent to the VXLAN GPEheader is the user information header, and the quantity of bytesoccupied by the user information header is less than or equal to 12.That is, the quantity of bytes occupied by the user information headeris less than a quantity of bytes occupied by an NSH that carries theuser access information. Therefore, encapsulation overheads are saved incomparison with a technology in which the user access information isstored in the NSH when the VXLAN GPE encapsulation is used.

Optionally, the user access information includes user access portinformation, the user information header includes a first field, and thefirst field is used to store the user access port information.

The user access information includes the user access port information,and the user information header may include only the first field tostore the user access port information, thereby further savingencapsulation overheads. Optionally, the first field may occupy 4 bytes.In addition, if the user information header includes only the firstfield used to store the user access port information, all bytes occupiedby the user information header are used to carry the user accessinformation. Therefore, transmission efficiency is improved incomparison with a technology in which when the user access informationis transmitted by using the NSH, there are at least 12 bytes that cannotbe used to store the user access information.

Optionally, the user access information further includes a protocol typeof the user access protocol packet, the user information header furtherincludes a second field, and the second field is used to indicate theprotocol type of the user access protocol packet.

In this embodiment of the present disclosure, the second field in theuser information header is defined, so that different values may be setfor the second field during encapsulation to encapsulate user accessprotocol packets of different protocol types, thereby ensuringextensibility of a protocol type of an encapsulated packet. The secondfield may occupy 1 byte.

Optionally, the user access information further includes a packet typeof the user access protocol packet, the user information header furtherincludes a third field, and the third field is used to indicate thepacket type of the user access protocol packet.

In this embodiment of the present disclosure, the third field may befurther defined in the user information header to indicate the packettype of the user access protocol packet. In this case, when theencapsulated packet is sent to a BRAS-CP, the BRAS-CP may decapsulatethe encapsulated packet more conveniently, thereby reducing complexityof parsing the packet by the BRAS-CP, so that the BRAS-CP can focus moreon processing an access protocol. The third field may occupy 1 byte.

Optionally, after the performing virtual extensible local area networkgeneric protocol extension VXLAN GPE encapsulation on the user accessprotocol packet based on the user access information, the method furtherincludes: sending an encapsulated user access protocol packet to abroadband remote access server control plane BRAS-CP, so that theBRAS-CP performs verification based on the user access informationcarried in the encapsulated user access protocol packet; and receivingan encapsulated reply packet sent by the BRAS-CP, where the encapsulatedreply packet is obtained by performing VXLAN GPE encapsulation on areply packet based on the user access information in a sameencapsulation manner as the user access protocol packet encapsulationafter the BRAS-CP performs verification on the user access information.

It should be noted that after the encapsulated user access protocolpacket is sent to the BRAS-CP, the BRAS-CP may generate the reply packetand encapsulate the reply packet based on the user access information ina same manner as the user access protocol packet encapsulation. For theBRAS-CP, the effects are also achieved: encapsulation overheads aresaved, processing difficulty is reduced, and transmission efficiency isimproved.

According to a second aspect, a BRAS system-based packet encapsulationapparatus is provided. The BRAS system-based packet encapsulationapparatus has a function of implementing the BRAS system-based packetencapsulation method behavior in the first aspect. The BRAS system-basedpacket encapsulation apparatus includes at least one module configuredto implement the BRAS system-based packet encapsulation method providedin the first aspect.

According to a third aspect, a packet encapsulation system is provided.The packet encapsulation system includes a BRAS-UP and a BRAS-CP.

The BRAS-UP is configured to obtain user access informationcorresponding to a user access protocol packet when receiving the useraccess protocol packet.

The BRAS-UP is further configured to: perform virtual extensible localarea network generic protocol extension VXLAN GPE encapsulation on theuser access protocol packet based on the user access information, andsend an encapsulated user access protocol packet to the BRAS-CP.

A VXLAN GPE encapsulation structure includes a VXLAN GPE header, a valueof an encapsulation protocol field of the VXLAN GPE header is a presetvalue, the preset value is used to indicate that the VXLAN GPEencapsulation structure includes a user information header, the userinformation header is used to store the user access information, theuser information header is located after the VXLAN GPE header and isadjacent to the VXLAN GPE header, and a quantity of bytes occupied bythe user information header is less than or equal to 12.

The BRAS-CP is configured to decapsulate the encapsulated user accessprotocol packet after receiving the encapsulated user access protocolpacket, to obtain the user access information and the user accessprotocol packet.

The BRAS-CP is further configured to: verify the user accessinformation, generate a reply packet after the verification, encapsulatethe reply packet based on the user access information in a sameencapsulation manner as the user access protocol packet encapsulation,and send an encapsulated reply packet to the BRAS-UP.

According to a fourth aspect, a BRAS system-based packet encapsulationapparatus is provided. A structure of the BRAS system-based packetencapsulation apparatus includes a processor and a memory, and thememory is configured to: store a program that supports the BRASsystem-based packet encapsulation apparatus in performing the BRASsystem-based packet encapsulation method provided in the first aspect,and store data used to implement the BRAS system-based packetencapsulation method provided in the first aspect. The processor isconfigured to execute the program stored in the memory. An operationapparatus of the storage device may further include a communicationsbus, and the communications bus is configured to establish a connectionbetween the processor and the memory.

According to a fifth aspect, a computer readable storage medium isprovided. The computer readable storage medium stores an instruction.When the instruction runs on a computer, the computer performs the BRASsystem-based packet encapsulation method in the first aspect.

According to a sixth aspect, a computer program product including aninstruction is provided. When the instruction runs on a computer, thecomputer performs the BRAS system-based packet encapsulation method inthe first aspect.

Technical effects achieved in the second aspect, the third aspect, thefourth aspect, the fifth aspect, and the sixth aspect are similar tothose achieved by using corresponding technical means in the firstaspect. Details are not described again herein.

The technical solutions provided have the following beneficial effects:After the user access protocol packet is received, the VXLAN GPEencapsulation may be performed on the user access protocol packet basedon the user access information. The VXLAN GPE encapsulation structureincludes the VXLAN GPE header, the value of the encapsulation protocolfield of the VXLAN GPE header is the preset value, the preset value isused to indicate that the VXLAN GPE encapsulation structure includes theuser information header, the user information header is used to storethe user access information, the user information header is locatedafter the VXLAN GPE header and is adjacent to the VXLAN GPE header, andthe quantity of bytes occupied by the user information header is lessthan or equal to 12. The VXLAN GPE encapsulation structure is used toencapsulate a packet, and an encapsulated packet has good backwardcompatibility. Therefore, a problem of incompatibility caused bymodifying standard VXLAN encapsulation is resolved. In addition, thequantity of bytes occupied by the user information header added to theVXLAN GPE encapsulation structure is less than or equal to 12, and anNSH that does not carry the user access information occupies at least 12bytes. That is, the quantity of bytes occupied by the user informationheader is less than a quantity of bytes occupied by an NSH that carriesthe user access information. Therefore, encapsulation overheads aresaved in comparison with a technology in which the user accessinformation is carried in an NSH introduced when the VXLAN GPEencapsulation is used. In addition, for some BRAS devices that usehigh-performance forwarding chips, a problem that an encapsulated packetcannot be processed or is more difficult to process due to anexcessively long header is avoided.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1A is a structural diagram of an NSH according to an embodiment ofthe present disclosure;

FIG. 1B is an implementation environment diagram of a BRAS system-basedpacket encapsulation method according to an embodiment of the presentdisclosure;

FIG. 2 is a schematic structural diagram of a computer device accordingto an embodiment of the present disclosure;

FIG. 3A is a flowchart of a BRAS system-based packet encapsulationmethod according to an embodiment of the present disclosure;

FIG. 3B is a structural diagram of VXLAN GPE encapsulation according toan embodiment of the present disclosure;

FIG. 3C is a structural diagram of a VXLAN GPE header according to anembodiment of the present disclosure;

FIG. 3D is a structural diagram of a user information header accordingto an embodiment of the present disclosure;

FIG. 3E is a structural diagram of an encapsulated packet headeraccording to an embodiment of the present disclosure;

FIG. 4 is a flowchart of accessing a network by user equipment in anIPoE access scenario in a BRAS system according to an embodiment of thepresent disclosure;

FIG. 5A is a schematic structural diagram of a BRAS system-based packetencapsulation apparatus according to an embodiment of the presentdisclosure; and

FIG. 5B is a schematic structural diagram of another BRAS system-basedpacket encapsulation apparatus according to an embodiment of the presentdisclosure.

DESCRIPTION OF EMBODIMENTS

To make the objectives, technical solutions, and advantages clearer, thefollowing further describes the implementations in detail with referenceto the accompanying drawings.

For ease of subsequent description, terms used in embodiments of thepresent disclosure are first explained before the embodiments of thepresent disclosure are explained and described in detail.

A BRAS system is a system including a plurality of BRAS devices. Thesystem is mainly configured to implement functions in two aspects: aforwarding plane function and user management and control functions,where the former is used to converge and forward a plurality of types ofservices, and the latter is used to fit an authentication system, anaccounting system, a customer management system, and a service policycontrol system to perform authentication, accounting, management, andthe like on user access.

A BRAS-CP is a dedicated server or server cluster configured to:separate user management and control functions implemented by using aplurality of BRAS devices in a conventional BRAS system from aforwarding plane function, and centralize the user management andcontrol functions.

A BRAS-UP includes a plurality of BRAS devices, and is configured toimplement a conventional control plane function such as routing ormulticast and a forwarding plane function such as traffic forwarding ortraffic statistics collection that are of the conventional BRAS system.

During packet encapsulation, an NSH is added by a device or anapplication featuring service classification. The NSH usually includesthree parts of content. The first part is NSH basic header informationthat occupies a total of 4 bytes. The second part is service pathinformation that occupies 4 bytes. The service path information isdetermined by the device that adds the NSH, and is used to indicate aservice path through which an encapsulated packet needs to pass. Thethird part is metadata information, and the metadata information ismetadata required by a network device on the service path through whichthe encapsulated packet needs to pass.

As shown in FIG. 1A, the NSH basic header information in the first partincludes version information (Ver), an 0 bit, a C bit, six R bits, alength information (Length) field, a metadata type (MD Type), and a nextprotocol field, where the next protocol field is also referred to as anencapsulation protocol field. The 0 bit is used to indicate whethercontent of the encapsulated packet is operation and maintenanceinformation. When the 0 bit is 1, it indicates that the content of theencapsulated packet is the operation and maintenance information. The Cbit is used to indicate whether the metadata information in the thirdpart includes user-defined metadata. When the C bit is 1, it indicatesthat the metadata information in the third part includes theuser-defined metadata. The six R bits are reserved. A value of thelength field is used to indicate a quantity of bytes occupied by theNSH, and the length field occupies 6 bits. The MD type is used toindicate whether a metadata format in the third part has a fixed length.When MD Type=0x1, it indicates that the metadata format in the thirdpart has a fixed length of 4 bytes, or when MD Type=0x2, it indicatesthat the metadata format in the third part has a length greater than 4bytes.

The service path information in the second part includes a service pathidentifier (SPI) and a service index (SI). The service path identifieroccupies 3 bytes, and the service index occupies 1 byte.

The third part is a variable length context header, and informationstored in the variable length context header is the metadatainformation. Based on the foregoing description, it may be learned thatwhen MD Type=0x1, this part has a fixed length of only 4 bytes, and whenMD Type=0x2, the part is 4 bytes aligned and is variable in length.

In a technology in which when the user access information is transmittedby using the NSH, when a BRAS-UP encapsulates a user access protocolpacket through VXLAN GPE, this is implemented by introducing the NSHafter a VXLAN GPE header. User access information is stored in the thirdpart. In this case, the third part is 4-byte aligned and is variable inlength. When the user access information is carried in the third part ofthe NSH, the first 4 bytes occupied by the third part are used to storebasic information, and the user access information is stored from the5th byte. It is assumed that the user access information occupies 6bytes. Because the third part is 4-byte aligned, actually the third partoccupies 8 bytes. In other words, when the user access informationoccupies 6 bytes, the NSH occupies at least 20 bytes.

After the terms used in the embodiments of the present disclosure areexplained, the following describes an implementation environment in theembodiments of the present disclosure.

FIG. 1B is an implementation environment diagram of a BRAS system-basedpacket encapsulation method according to an embodiment of the presentdisclosure. As shown in FIG. 1B, the implementation environment includesuser equipment 101, a BRAS-UP 102, a BRAS-CP 103, a core router (CR)104, an authentication, authorization, and accounting (AAA) server 105,and a Dynamic Host Configuration Protocol (DHCP) server 106. The userequipment 101 may establish a communication connection to the BRAS-UP102, the BRAS-UP 102 may establish a communication connection to the CR104, and the CR 104 may establish a communication connection to theBRAS-CP 103. In other words, the BRAS-UP 102 and the BRAS-CP 103 mayimplement VXLAN-based communication through the communication connectionbetween the BRAS-UP 102 and the CR 104 and the communication connectionbetween the BRAS-CP 103 and the CR 104. In addition, the BRAS-CP 103 mayseparately establish a communication connection to the AAA server 105and the DHCP server 106.

It should be noted that user equipment 101 may be connected to theinternet through the communication connection to the BRAS-UP 102 and thecommunication connection between the BRAS-UP 102 and the CR 104, so asto obtain a network service. When the user equipment 101 accessesbroadband through dialing or in another manner, the user equipment 101may send a user access protocol packet to the BRAS-UP 102 through thecommunication connection to the BRAS-UP 102. The BRAS-UP 102 may add, toa beginning part in the received user access protocol packet, a userinformation header that stores user access information, and encapsulatesthe user information header and the user access protocol packet. Then,the BRAS-UP 102 sends an encapsulated packet to the BRAS-CP 103 over theCR 104. The BRAS-CP 103 may decapsulate the received encapsulated packetto obtain the user access information, and interact with the AAA server105 and the DHCP server 106 based on the user access information, so asto perform authentication, accounting, and the like on the userequipment 101.

It should be further noted that the user access protocol packet istransmitted between the BRAS-UP 102 and the BRAS-CP 103 transmit basedon a VXLAN. Therefore, the BRAS-UP 102 and the BRAS-CP 103 each includea VXLAN tunnel end point (VTEP). In addition, the BRAS-CP 103 furtherincludes an access module. Specifically, the VTEP of the BRAS-UP 102 ismainly responsible for performing VXLAN GPE encapsulation on the useraccess protocol packet, decapsulating a received encapsulated replypacket, and sending a decapsulated reply packet to the user equipment101. The VTEP of the BRAS-CP 103 is mainly responsible for decapsulatinga received encapsulated user access protocol packet, and performingVXLAN GPE encapsulation on a reply packet generated by the accessmodule. The access module is mainly responsible for processing the useraccess protocol packet, generating an authentication request packetcarrying the user access information, and sending the authenticationrequest packet to the AAA server 105 to attempt to authenticate the userequipment 101. In addition, the access module may request addressassignment from the DHCP server 106 after the AAA server 105 isauthenticated, and generate a reply packet based on an obtained assignedaddress. Through protocol exchanges between the user equipment 101, theBRAS-UP 102, the BRAS-CP 103, the AAA server 105, and the DHCP server106, the user equipment 101 accesses the broadband, and the BRAS systemstarts accounting for the user equipment 101.

FIG. 2 is a schematic structural diagram of a computer device accordingto an embodiment of the present disclosure. The BRAS-UP and the BRAS-CPin FIG. 1B each may be implemented by using the computer device shown inFIG. 2. Referring to FIG. 2, the computer device includes at least oneprocessor 201, a communications bus 202, a memory 203, and at least onecommunications interface 204.

The processor 201 may be a general-purpose central processing unit(CPU), a microprocessor, an application-specific integrated circuit(ASIC), or one or more integrated circuits for controlling programexecution in the solution.

The communications bus 202 may include a path for transmittinginformation between the foregoing components.

The memory 203 may be a read-only memory (ROM) or another type of staticstorage device that may store static information and instructions, arandom-access memory (RAM) or another type of dynamic storage devicethat may store information and instructions, or may be an electricallyerasable programmable read-only memory (EEPROM), a compact discread-only memory (CD-ROM), another optical disc storage medium, opticaldisc storage medium (including a compact disc, a laser disc, an opticaldisc, a digital versatile disc, a Blu-ray disc, or the like), ormagnetic disk storage medium, another magnetic storage device, or anyother medium that may be used to carry or store expected program code ina form of an instruction or a data structure and that may be accessed bya computer. This does not constitute a limitation herein. The memory 203may exist independently, and is connected to the processor 201 by usingthe communications bus 202. Alternatively, the memory 203 may beintegrated with the processor 201.

The communications interface 204 may be any apparatus like atransceiver, and is configured to communicate with another device orcommunications network, such as an Ethernet network, a radio accessnetwork (RAN), or a wireless local area network (WLAN).

During specific implementation, in an embodiment, the processor 201 mayinclude one or more CPUs, for example, a CPU 0 and a CPU 1 shown in FIG.2.

During specific implementation, in an embodiment, the computer devicemay include a plurality of processors, such as the processor 201 and aprocessor 205 shown in FIG. 2. Each of these processors may be asingle-core (single-CPU) processor, or may be a multi-core (multi-CPU)processor. The processor herein may be one or more devices, circuits,and/or a processing core configured to process data (such as a computerprogram instruction).

During specific implementation, in an embodiment, the computer devicemay further include an output device 206 and an input device 207. Theoutput device 206 communicates with the processor 201, and may displayinformation in a plurality of manners. For example, the output device206 may be a liquid crystal display (LCD), a light-emitting diode (LED)display device, a cathode-ray tube (CRT) display device, or a projector.The input device 207 communicates with the processor 201, and mayreceive user input in a plurality of manners. For example, the inputdevice 207 may be a mouse, a keyboard, a touchscreen device, or asensing device.

The foregoing computer device may be a general-purpose computer deviceor a dedicated computer device. During specific implementation, thecomputer device may be a desktop, a portable computer, a network server,a personal digital assistant (PDA), a mobile phone, a tablet computer, awireless terminal device, a communications device, or an embeddeddevice. A type of the computer device is not limited in this embodimentof the present disclosure.

The memory 203 is configured to store program code used to execute thesolutions, and the processor 201 controls the execution. The processor201 is configured to execute program code 208 stored in the memory 203.The program code 208 may include one or more software modules. TheBRAS-UP or the BRAS-CP shown in FIG. 1B may encapsulate a receivedpacket by using the processor 201 and the one or more software modulesin the program code 208 in the memory 203.

Based on the foregoing description, after the terms and theimplementation environment in the embodiments of the present disclosureare explained, a specific implementation process in which a BRAS-UPperforms VXLAN GPE encapsulation on a received user access protocolpacket is described in detail below with reference to FIG. 3A to FIG.3E.

FIG. 3A is a flowchart of a BRAS system-based packet encapsulationmethod according to an embodiment of the present disclosure. As shown inFIG. 3A, the packet encapsulation method is used on the BRAS-UP, and themethod includes the following steps:

Step 301: Receive a user access protocol packet sent by user equipment.

When the user equipment accesses broadband through dialing or in anothermanner, the user equipment may send the user access protocol packet tothe BRAS-UP over an access network.

Step 302: Obtain user access information corresponding to the useraccess protocol packet.

When receiving the user access protocol packet, the BRAS-UP maydetermine user access port information corresponding to the user accessprotocol packet based on a port on which the user access protocol packetis received, and the BRAS-UP may further determine a correspondingprotocol type and packet type based on the user access protocol packet.The user access information may include the following: the user accessport information used to indicate the port on which the user accessprotocol packet is received; the protocol type of the user accessprotocol packet; and the specific packet type of the user accessprotocol packet.

Step 303: Perform VXLAN GPE encapsulation on the user access protocolpacket based on the user access information.

After obtaining the user access information, the BRAS-UP may add a userinformation header to a beginning part of the user access protocolpacket. The user information header is used to store the user accessinformation corresponding to the user access protocol packet. Then theBRAS-UP may set a next protocol field of a VXLAN GPE header in a VXLANGPE encapsulation structure, that is, a value of an encapsulationprotocol field, to a preset value. The preset value is used to indicatethat the user information header is included in the VXLAN GPEencapsulation structure, and the user information header is locatedafter the VXLAN GPE header and is adjacent to the VXLAN GPE header. Inaddition, the BRAS-UP may further set, to a preset value, a value of aflag bit that is in the VXLAN GPE encapsulation structure and that isspecifically used to indicate whether the next protocol field is valid.The preset value is used to indicate that the next protocol field isvalid in the current VXLAN GPE encapsulation structure.

It should be noted that, as shown in FIG. 3B, the VXLAN GPEencapsulation structure includes a layer 2 (L2) header, an InternetProtocol (IP) header, a user datagram protocol (UDP) header, and theVXLAN GPE header. The L2 header is an external Ethernet header thatoccupies 14 or 18 bytes, and the L2 header is corresponding to a mediaaccess control (MAC) address used by the Ethernet. The IP headeroccupies 20 bytes, the UDP header occupies 8 bytes, and the VXLAN GPEheader occupies 8 bytes. In a technology in which when the user accessinformation is transmitted by using the NSH, when the user accessprotocol packet is encapsulated through the VXLAN GPE, an NSH is furtherincluded after the VXLAN GPE header. Based on the foregoing description,when the user access information occupies 6 bytes, the NSH occupies atleast 20 bytes.

Further, as shown in FIG. 3C, the VXLAN GPE header includes the nextprotocol field that usually occupies 1 byte, and a value of the nextprotocol field is used to indicate a protocol type of content of a partadjacent to the VXLAN GPE header and located after the VXLAN GPE header.When the value of the next protocol field is different, the protocoltype of the part that is located after the VXLAN GPE header and isadjacent to the VXLAN GPE header is different, and consequently a typeof the user access protocol packet obtained through encapsulation isalso different. Currently, in the technology in which when the useraccess information is transmitted by using the NSH, the value of thenext protocol field and a corresponding protocol type are shown inTable 1. It may be learned from Table 1 that when the value of the nextprotocol field ranges from 0 to 5, there is a specific protocol typecorresponding to the value. When the value of the next protocol field is4, it indicates that the NSH immediately follows the VXLAN GPE header.In this case, an encapsulated user access protocol packet is an NSHpacket. However, there are no specific protocol types defined for valuesfrom 6 to 253. Therefore, in this embodiment of the present disclosure,any value may be taken from the value range from 6 to 253 as a presetvalue, and a protocol type corresponding to the preset value is definedas a user information header. That is, when the next protocol field isthe preset value, it indicates that the next Protocol field isimmediately followed by the user information header. In this case, anencapsulated user access protocol packet is a packet including the userinformation header.

TABLE 1 Value of a next protocol field and a corresponding protocol typein a related technology Next protocol Protocol type 0 Reserved 1Internet protocol version 4 (IPv4) 2 Internet protocol version 6 (IPv6)3 Ethernet 4 NSH 5 Multi-protocol label switching (MPLS) 6 to 253Undefined (Unassigned) 254  Experiment 1 255  Experiment 2

It is assumed that in this embodiment of the present disclosure, thevalue of the preset value is defined as 6. In this case, the value ofthe next protocol field and the corresponding protocol type are shown inTable 2. That is, if the BRAS-UP is expected to add the user informationheader at a location adjacent to and after the VXLAN GPE header whenencapsulating the user access protocol packet, the BRAS-UP needs to setthe value of the next protocol field in the VXLAN GPE header to 6. Theuser information header can also be referred to as a control-planeuser-plane (CU) separated header.

TABLE 2 Value of a next protocol field and a corresponding protocol typeaccording to this embodiment of the present disclosure Next protocolProtocol type 0 Reserved 1 IPv4 2 IPv6 3 Ethernet 4 NSH 5 MPLS 6 Userinformation header 7 to 253 Undefined (Unassigned) 254  Experiment 1255  Experiment 2

It should be further noted that, as shown in FIG. 3C, the VXLAN GPEheader further includes an identifier field that occupies 1 byte. Theidentifier field includes three reserved R bits, version information(Ver), an I bit, a P bit, and an O bit. The 5th bit counting from 0 inthe identifier field is the P bit. When a value of the P bit is 1, itindicates that the next protocol field in the VXLAN GPE header has ameaning. When a value of the P bit is 0, it indicates that the nextprotocol field in the VXLAN GPE header has no meaning. Therefore, aftersetting the value of the next protocol field to the preset value, theBRAS-UP further needs to set the value of the P bit to 1, so that thevalue of the next protocol field can have a meaning.

In addition to the next protocol field and the identifier fielddescribed above, as shown in FIG. 3C, the VXLAN GPE header furtherincludes 3 reserved bytes and a VXLAN network identifier (VNI).

The foregoing describes the setting of the VXLAN GPE header by theBRAS-UP when the VXLAN GPE encapsulation is performed on the user accessprotocol packet and the user information header added to the user accessprotocol packet. Before setting the VXLAN GPE header, the BRAS-UP firstneeds to store the user access information in the user informationheader. The following describes a specific implementation process inwhich the user access information is stored in the user informationheader in this embodiment of the present disclosure.

In this embodiment of the present disclosure, the user informationheader includes a first field. The BRAS-UP may store the user accessport information of the user access information in the first field.Optionally, the first field may occupy 4 bytes. In the first field, inaddition to the user access port information, more other user accessinformation may be stored.

Optionally, in addition to including the first field, the userinformation header may further include a second field. A value of thesecond field may be used to indicate a protocol type of an encapsulateduser access protocol packet. Optionally, types of protocol types arelimited. Therefore, a quantity of values of the second field is limited,and a value within 1 byte can meet the value of the second field.Therefore, the second field may occupy 1 byte. In addition, the secondfield may be located before the first field. Specifically, the secondfield may be defined as a next protocol field, and a value of the nextprotocol field in the user information header and a correspondingprotocol type may be defined, as shown in Table 3.

TABLE 3 Value of a next protocol field in a user information header anda corresponding protocol type Next protocol Protocol type 0 Reserved 1IPv4 2 IPv6 3 Ethernet

In this embodiment of the present disclosure, by defining the nextprotocol field in the user information header, the BRAS-UP may set adifferent value for the next protocol field in the user informationheader to encapsulate a user access protocol packet of a differentprotocol type. That is, based on the different value of the nextprotocol field in the user information header, the BRAS-UP mayencapsulate a layer 3 Ethernet packet in a point-to-point protocol overEthernet (PPPoE) access scenario, or may encapsulate a layer 3 Ethernetpacket in an IP over Ethernet (IPoE) access scenario, or may encapsulatea layer 3 Ethernet packet in an L2 tunneling protocol (L2TP) accessscenario, or the like, so as to ensure extensibility of a protocol typeof an encapsulated packet.

Optionally, in addition to including the first field, the userinformation header may further include a third field. A value of thethird field may be used to indicate a packet type of the encapsulateduser access protocol packet. Optionally, types of packet types arelimited. Therefore, a quantity of values of the third field is limited,and a value within 1 byte can meet the value of the third field.Therefore, the third field may occupy 1 byte. In addition, the thirdfield may be located before the first field, and the packet type refersto a most specific type of an encapsulated packet. A protocol type suchas the PPPoE or the IPv4 cannot be used as the packet type, that is, apacket type corresponding to the value of the third field cannot bedefined as the protocol type such as the PPPoE or the IPv4.Specifically, the value of the third field and a definition of thecorresponding packet type may be shown in Table 4. It should be notedthat the value of the third field and the corresponding packet typeshown in Table 4 are merely examples provided in this embodiment of thepresent disclosure, and do not represent that all possible values andpacket types are included.

TABLE 4 Value of a third field in a user information header and acorresponding packet type Third field Packet type 0 × 0 Reserved 0 × 1PPPoE PADI [RFC 2516] 0 × 2 PPPoE PADR [RFC 2516] 0 × 3 PPPoE SESSION[RFC 2516] 0 × 4 DHCP discover [RFC 2131] 0 × 5 DHCP request [RFC 2131]0 × 6 DHCPv6 request [RFC 3315] 0 × 7 DHCPv6 solicit [RFC 3315] 0 × 8IPv6 RS [RFC 4861] 0 × 9 IPv6 NS [RFC 4861] 0 × a IPv6 NA [RFC 4861]

In this embodiment of the present disclosure, when the user informationheader includes the third field, the value of the third field indicatesin detail the packet type of the encapsulated packet. Therefore, whenthe BRAS-UP sends the encapsulated packet to the BRAS-CP, the BRAS-CPmay decapsulate the encapsulated packet more conveniently, therebyreducing complexity of parsing the packet by the BRAS-CP, so that theBRAS-CP can focus more on processing an access protocol.

Optionally, based on the foregoing description, it may be learned thatthe user information header may include only the first field, or mayinclude the first field and the second field, or may include the firstfield and the third field. Certainly, the user information header mayalternatively include the first field, the second field, and the thirdfield. When the user information header includes the first field, thesecond field, and the third field, a structure of the user informationheader may be shown in FIG. 3D, where the first field occupies 4 bytes,the second field occupies 1 byte, the third field also occupies 1 byte,and both the second field and the third field are located before thefirst field.

It is assumed that the user information header includes the first field,the second field, and the third field, the first field occupies 4 bytes,the second field occupies 1 byte, and the third field occupies 1 byte,the BRAS-UP encapsulates the received user access protocol packet basedon the foregoing VXLAN GPE encapsulation structure and the userinformation header, and an encapsulated packet header is shown in FIG.3E.

In this embodiment of the present disclosure, after receiving the useraccess protocol packet, the BRAS-UP may perform the VXLAN GPEencapsulation on the user access protocol packet based on the useraccess information. The value of the encapsulation protocol field of theVXLAN GPE header in the VXLAN GPE encapsulation structure is the presetvalue. The preset value is used to indicate that the VXLAN GPEencapsulation structure includes the user information header. The userinformation header is located after the VXLAN GPE header and is adjacentto the VXLAN GPE header, and a quantity of bytes occupied by the userinformation header is less than or equal to 12. The VXLAN GPEencapsulation structure is used to encapsulate a packet, and anencapsulated packet has good backward compatibility. Therefore, aproblem of incompatibility caused by modifying standard VXLANencapsulation is resolved. In addition, the quantity of bytes occupiedby the user information header added to the VXLAN GPE encapsulationstructure is less than or equal to 12, and an NSH that does not carrythe user access information occupies at least 12 bytes. That is, thequantity of bytes occupied by the user information header is less than aquantity of bytes occupied by an NSH that carries the user accessinformation. Therefore, encapsulation overheads are saved in comparisonwith a technology in which the user access information is carried in anNSH introduced when the VXLAN GPE encapsulation is used. In addition,for some BRAS-UPs that use high-performance forwarding chips, a problemthat an encapsulated packet cannot be processed or is more difficult toprocess due to an excessively long header is avoided. In addition, allbytes occupied by the user information header provided in thisembodiment of the present disclosure may be used to carry the useraccess information. Therefore, transmission efficiency is improved incomparison with a case in which when the user access information istransmitted by using the NSH, there are at least 12 bytes that cannot beused to store the user access information.

The foregoing embodiment mainly describes the process of encapsulatingthe received user access protocol packet by the BRAS-UP. Based on thedescription of the foregoing implementation environment, it may belearned that after the BRAS-UP encapsulates the received user accessprotocol packet in the foregoing manner, the BRAS-UP may send theencapsulated packet to the BRAS-CP, and the BRAS-CP may generate a replypacket after authentication. After generating the reply packet, theBRAS-CP may also perform the VXLAN GPE encapsulation on the reply packetbased on the user access information by using the method for performingthe VXLAN GPE encapsulation on the user access protocol packet describedin the foregoing embodiment, and send the encapsulated reply packet tothe BRAS-UP.

The foregoing embodiment mainly describes the method for performing theVXLAN GPE encapsulation on the user access protocol packet by theBRAS-UP based on the user access information. The following describes,by using an IPoE access scenario in a BRAS system as an example, aspecific process in which a BRAS-UP and a BRAS-CP enable user equipmentto access broadband based on the packet encapsulation method provided inthe embodiments of the present disclosure by exchanging protocols withthe user equipment, an AAA server, and a DHCP server.

FIG. 4 is a flowchart of accessing a network by the user equipment inthe IPoE access scenario in the BRAS system according to an embodimentof the present disclosure. As shown in FIG. 4, the process includes thefollowing steps.

Step 401: The user equipment sends a user access protocol packet to theBRAS-UP over an access network.

Step 402: When receiving the user access protocol packet, the BRAS-UPobtains user access information corresponding to the user accessprotocol packet, and performs VXLAN GPE encapsulation on the user accessprotocol packet based on the user access information.

A VTEP of the BRAS-UP performs the VXLAN GPE encapsulation on the useraccess protocol packet by using the packet encapsulation methoddescribed in the foregoing embodiment. For a specific encapsulationmethod, refer to the foregoing embodiment. Details are not describedherein again.

Step 403: The BRAS-UP sends an encapsulated user access protocol packetto the BRAS-CP.

The BRAS-UP communicates with the BRAS-CP based on a VXLAN, andtherefore the BRAS-CP also includes a VTEP. The VTEP of the BRAS-UPsends the encapsulated user access protocol packet to the VTEP of theBRAS-CP.

Step 404: The BRAS-CP processes the received encapsulated user accessprotocol packet and generates an authentication request packet carryingthe user access information.

After receiving the encapsulated user access protocol packet, the VTEPof the BRAS-CP may decapsulate the encapsulated user access protocolpacket, to obtain the user access information and the user accessprotocol packet. Then the VTEP of the BRAS-CP may send the obtained useraccess information and user access protocol packet to an access moduleof the BRAS-CP. The access module processes the user access protocolpacket and generates the authentication request packet carrying the useraccess information. The authentication request packet is a packetgenerated by the access module and used to request authentication fromthe AAA server.

Step 405: The BRAS-CP sends the authentication request packet to the AAAserver.

Step 406: The AAA server attempts to authenticate the user equipmentbased on the received authentication request packet.

After receiving the authentication request packet, the AAA server mayattempt to authenticate the user equipment corresponding to the useraccess information based on the user access information carried in theauthentication request packet.

Step 407: After the authentication succeeds, the AAA server may send anauthentication reply to the BRAS-CP.

Step 408: After receiving the authentication reply sent by the AAAserver, the BRAS-CP sends an address request to the DHCP server.

After authenticating the user equipment, the AAA server may send theauthentication reply to the access module of the BRAS-CP. Afterreceiving the authentication reply, the access module of the BRAS-CP maysend the address request to the DHCP server to request the DHCP serverto assign an address.

Step 409: When receiving the address request, the DHCP server assigns anaddress to the user equipment.

When receiving the address request, the DHCP server may search an IPaddress pool of the DHCP server for a valid and available IP address.

Step 410: The DHCP server sends, to the BRAS-CP, a response messagecarrying the assigned address.

Step 411: When receiving the response message sent by the DHCP server,the BRAS-CP generates a reply packet based on the response message andperforms VXLAN GPE encapsulation on the reply packet.

When receiving the response message, the access module of the BRAS-CPmay generate the reply packet based on the IP address carried in theresponse message, and then the access module of the BRAS-CP may send thereply packet to the VTEP of the BRAS-CP. The VTEP of the BRAS-CPencapsulates the reply packet based on the user access informationobtained during the decapsulation in step 404 by using the packetencapsulation method provided in the foregoing embodiment.

Step 412: Send an encapsulated reply packet to the user equipment byusing the BRAS-UP.

In this embodiment of the present disclosure, when the user equipmentaccesses the broadband, the BRAS-UP may perform the VXLAN GPEencapsulation on the user access protocol packet based on the useraccess information, and the BRAS-CP may perform the VXLAN GPEencapsulation on the generated reply packet based on the user accessinformation. A value of an encapsulation protocol field of a VXLAN GPEheader in the VXLAN GPE encapsulation structure is a preset value, thepreset value is used to indicate that the VXLAN GPE encapsulationstructure includes a user information header, the user informationheader is used to store the user access information, the userinformation header is located after the VXLAN GPE header and is adjacentto the VXLAN GPE header, and a quantity of bytes occupied by the userinformation header is less than or equal to 12. The quantity of bytesoccupied by the user information header added to the VXLAN GPEencapsulation structure is less than or equal to 12, and an NSH thatdoes not carry the user access information occupies at least 12 bytes.That is, the quantity of bytes occupied by the user information headeris less than a quantity of bytes occupied by an NSH that carries theuser access information. Therefore, encapsulation overheads are saved incomparison with a technology in which the user access information iscarried in an NSH introduced when the VXLAN GPE encapsulation is used.In addition, for some BRAS-UPs and BRAS-CPs that use high-performanceforwarding chips, a problem that an encapsulated packet cannot beprocessed or is more difficult to process due to an excessively longheader is avoided. In addition, all bytes occupied by the userinformation header provided in this embodiment of the present disclosuremay be used to carry the user access information. Therefore,transmission efficiency is improved in comparison with a case in whichwhen the user access information is transmitted by using the NSH, thereare at least 12 bytes that cannot be used to store the user accessinformation.

After the specific implementation process of the embodiments of thepresent disclosure is explained in detail, the following describesapparatuses provided in the embodiments of the present disclosure.

FIG. 5A shows a BRAS system-based packet encapsulation apparatusaccording to an embodiment of the present disclosure. The BRASsystem-based packet encapsulation apparatus is configured to perform thepacket encapsulation method shown in FIG. 3A. As shown in FIG. 5A, theapparatus includes an obtaining module 501 and an encapsulation module502.

The obtaining module 501 is configured to perform step 302 in theforegoing embodiment.

The encapsulation module 502 is configured to perform step 303 in theforegoing embodiment.

Optionally, the user access information includes user access portinformation, user information header includes a first field, and thefirst field is used to store the user access information.

Optionally, the user access information further includes a protocol typeof the user access protocol packet, the user information header furtherincludes a second field, and the second field is used to indicate theprotocol type of the user access protocol packet.

Optionally, the user access information further includes a packet typeof the user access protocol packet, the user information header furtherincludes a third field, and the third field is used to indicate thepacket type of the user access protocol packet.

Optionally, referring to FIG. 5B, the apparatus further includes: asending module 503 configured to send an encapsulated user accessprotocol packet to a broadband remote access server control planeBRAS-CP, so that the BRAS-CP performs verification based on the useraccess information carried in the encapsulated user access protocolpacket; and a receiving module 504 configured to receive an encapsulatedreply packet sent by the BRAS-CP, where the encapsulated reply packet isobtained by performing VXLAN GPE encapsulation on a reply packet basedon the user access information in a same encapsulation manner as theuser access protocol packet encapsulation after the BRAS-CP performsverification on the user access information.

In conclusion, in this embodiment of the present disclosure, the BRAS-UPmay perform the VXLAN GPE encapsulation on the user access protocolpacket based on the user access information, and the BRAS-CP may performthe VXLAN GPE encapsulation on the generated reply packet based on theuser access information. A value of an encapsulation protocol field of aVXLAN GPE header in the VXLAN GPE encapsulation structure is a presetvalue, the preset value is used to indicate that the VXLAN GPEencapsulation structure includes a user information header, the userinformation header is used to store the user access information, theuser information header is located after a specific field and isadjacent to the specific field, and a quantity of bytes occupied by theuser information header is less than or equal to 12. The quantity ofbytes occupied by the user information header added to the VXLAN GPEencapsulation structure is less than or equal to 12, and an NSH thatdoes not carry the user access information occupies at least 12 bytes.That is, the quantity of bytes occupied by the user information headeris less than a quantity of bytes occupied by an NSH that carries theuser access information. Therefore, encapsulation overheads are saved incomparison with the technology in which the user access information iscarried in an NSH introduced when the VXLAN GPE encapsulation is used.In addition, for some BRAS-UPs and BRAS-CPs that use high-performanceforwarding chips, a problem that an encapsulated packet cannot beprocessed or is more difficult to process due to an excessively longheader is avoided. In addition, all bytes occupied by the userinformation header provided in this embodiment of the present disclosuremay be used to carry the user access information. Therefore,transmission efficiency is improved in comparison with a case in whichwhen the user access information is transmitted by using the NSH, thereare at least 12 bytes that cannot be used to store the user accessinformation.

After the BRAS system-based packet encapsulation apparatus provided inthe embodiments of the present disclosure is described, the embodimentsof the present disclosure further provide a packet encapsulation system.The packet encapsulation system includes a BRAS-UP and a BRAS-CP, wherethe BRAS-UP may include a plurality of BRAS devices, and the BRAS-CP maybe a dedicated server or server cluster.

The BRAS-UP is configured to obtain user access informationcorresponding to a user access protocol packet when receiving the useraccess protocol packet.

The BRAS-UP is further configured to: perform virtual extensible localarea network generic protocol extension VXLAN GPE encapsulation on theuser access protocol packet based on the user access information, andsend an encapsulated user access protocol packet to the BRAS-CP.

A VXLAN GPE encapsulation structure includes a VXLAN GPE header, a valueof an encapsulation protocol field of the VXLAN GPE header is a presetvalue, the preset value is used to indicate that the VXLAN GPEencapsulation structure includes a user information header, the userinformation header is used to store the user access information, theuser information header is located after the VXLAN GPE header and isadjacent to the VXLAN GPE header, and a quantity of bytes occupied bythe user information header is less than or equal to 12.

The BRAS-CP is configured to decapsulate the encapsulated user accessprotocol packet after receiving the encapsulated user access protocolpacket, to obtain the user access information and the user accessprotocol packet.

The BRAS-CP is further configured to: verify the user accessinformation, generate a reply packet after the verification, encapsulatethe reply packet based on the user access information in a sameencapsulation manner as the user access protocol packet encapsulation,and send an encapsulated reply packet to the BRAS-UP.

In this embodiment of the present disclosure, the BRAS-UP may performthe VXLAN GPE encapsulation on the user access protocol packet based onthe user access information, and the BRAS-CP may perform the VXLAN GPEencapsulation on the generated reply packet based on the user accessinformation. The value of the encapsulation protocol field of the VXLANGPE header in the VXLAN GPE encapsulation structure is the preset value,the preset value is used to indicate that the VXLAN GPE encapsulationstructure includes the user information header, the user informationheader is used to store the user access information, the userinformation header is located after a specific field and is adjacent tothe specific field, and the quantity of byes occupied by the userinformation header is less than or equal to 12. The quantity of bytesoccupied by the user information header added to the VXLAN GPEencapsulation structure is less than or equal to 12, and an NSH thatdoes not carry the user access information occupies at least 12 bytes.That is, the quantity of bytes occupied by the user information headeris less than a quantity of bytes occupied by an NSH that carries theuser access information. Therefore, encapsulation overheads are saved incomparison with a technology in which the user access information iscarried in an NSH introduced when the VXLAN GPE encapsulation is used.In addition, for some BRAS-UPs and BRAS-CPs that use high-performanceforwarding chips, a problem that an encapsulated packet cannot beprocessed or is more difficult to process due to an excessively longheader is avoided. In addition, all bytes occupied by the userinformation header provided in this embodiment of the present disclosuremay be used to carry the user access information. Therefore,transmission efficiency is improved in comparison with a case in whichwhen the user access information is transmitted by using the NSH, thereare at least 12 bytes that cannot be used to store the user accessinformation.

It should be noted that when the BRAS system-based packet encapsulationapparatus provided in the foregoing embodiments performs packetencapsulation, division of the foregoing function modules is used onlyas an example for description. During actual application, the foregoingfunctions may be allocated as required to different function modules forimplementation. To be specific, an internal structure of the device isdivided into different function modules to implement all or some of thefunctions described above. In addition, the BRAS system-based packetencapsulation apparatus provided in the foregoing embodiments and theBRAS system-based packet encapsulation method embodiments pertain to asame concept. For a specific implementation process of the BRASsystem-based packet encapsulation apparatus, refer to the methodembodiments. Details are not described herein again.

All or some of the foregoing embodiments may be implemented by software,hardware, firmware, or any combination thereof. When software is used toimplement the embodiments, the embodiments may be implemented completelyor partially in a form of a computer program product. The computerprogram product includes one or more computer instructions. When thecomputer instructions are loaded and executed on a computer, theprocedures or functions according to the embodiments of the presentdisclosure are all or partially generated. The computer may be ageneral-purpose computer, a dedicated computer, a computer network, oranother programmable apparatus. The computer instructions may be storedin a computer readable storage medium or may be transmitted from acomputer readable storage medium to another computer readable storagemedium. For example, the computer instructions may be transmitted fromone website, computer, server, or data center to another website,computer, server, or data center in a wired (for example, a coaxialcable, an optical fiber, or a digital subscriber line (DSL)) or wireless(for example, infrared, radio, or microwave) manner. The computerreadable storage medium may be any usable medium accessible by acomputer, or a data storage device, such as a server or a data center,integrating one or more usable media. The usable medium may be amagnetic medium (for example, a floppy disk, a hard disk, or a magnetictape), an optical medium (for example, a digital versatile disc (DVD)),a semiconductor medium (for example, a solid-state drive (SSD)), or thelike.

A person of ordinary skill in the art may understand that all or some ofthe steps of the embodiments may be implemented by using hardware or aprogram instructing related hardware. The program may be stored in acomputer readable storage medium. The storage medium may be a read-onlymemory, a magnetic disk, an optical disc, or the like.

The foregoing descriptions are not intended to limit this disclosure.Any modification, equivalent replacement, or improvement made withoutdeparting from the spirit and principle of this disclosure should fallwithin the protection scope of this disclosure.

What is claimed is:
 1. A method comprising: receiving a user accessprotocol packet; obtaining user access information corresponding to theuser access protocol packet; and performing virtual extensible localarea network generic protocol extension (VXLAN GPE) encapsulation on theuser access protocol packet and based on the user access information tocreate an encapsulated user access protocol packet, wherein theencapsulated user access protocol packet comprises a VXLAN GPE headerand a user information header located after and adjacent to the VXLANGPE header, wherein the VXLAN GPE header comprises an encapsulationprotocol field with a preset value, wherein the preset value indicatesthat the encapsulated user access protocol packet comprises the userinformation header, wherein the user information header stores the useraccess information; wherein the user access information comprises useraccess port information, wherein the user information header comprises afirst field, and wherein the first field comprises the user access portinformation.
 2. The method of claim 1, wherein the user informationheader is 12 or fewer bytes.
 3. The method of claim 1, wherein the userinformation header is not a network service header (NSH).
 4. The methodof claim 1, wherein the user information header comprises only the useraccess information.
 5. The method of claim 1, wherein the user accessinformation further comprises a protocol type of the user accessprotocol packet, wherein the user information header further comprises asecond field, and wherein the second field indicates the protocol type.6. The method of claim 1, wherein the user access information furthercomprises a packet type of the user access protocol packet, wherein theuser information header further comprises a third field, and wherein thethird field indicates the packet type.
 7. The method of claim 1, whereinafter performing the VXLAN GPE encapsulation, the method furthercomprises: sending the encapsulated user access protocol packet to abroadband remote access server control plane (BRAS-CP); and receiving anencapsulated reply packet from the BRAS-CP, wherein the encapsulatedreply packet is based on VXLAN GPE encapsulation of a reply packet usingthe user access information and a same encapsulation manner as for theuser access protocol packet.
 8. An apparatus comprising: a receiverconfigured to receive a user access protocol packet; and a processorcoupled to the receiver and configured to: obtain user accessinformation corresponding to the user access protocol packet; andperform virtual extensible local area network generic protocol extension(VXLAN GPE) encapsulation on the user access protocol packet and basedon the user access information to create an encapsulated user accessprotocol packet, wherein the encapsulated user access protocol packetcomprises a VXLAN GPE header and a user information header located afterand adjacent to the VXLAN GPE header, wherein the VXLAN GPE headercomprises an encapsulation protocol field with a preset value, whereinthe preset value indicates that the encapsulated user access protocolpacket comprises the user information header, wherein the userinformation header stores the user access information; wherein the useraccess information comprises user access port information, wherein theuser information header comprises a first field, and wherein the firstfield comprises the user access port information.
 9. The apparatus ofclaim 8, wherein the user information header is 12 or fewer bytes. 10.The apparatus of claim 8, wherein the user information header is not anetwork service header (NSH).
 11. The apparatus of claim 8, wherein theuser information header comprises only the user access information. 12.The apparatus of claim 8, wherein the user access information furthercomprises a protocol type of the user access protocol packet, whereinthe user information header further comprises a second field, andwherein the second field indicates the protocol type.
 13. The apparatusof claim 8, wherein the user access information further comprises apacket type of the user access protocol packet, wherein the userinformation header further comprises a third field, and wherein thethird field indicates the packet type.
 14. The apparatus of claim 8,further comprising a transmitter coupled to the processor and configuredto send the encapsulated user access protocol packet to a broadbandremote access server control plane (BRAS-CP), wherein the receiver isfurther configured to receive an encapsulated reply packet from theBRAS-CP, wherein the encapsulated reply packet is based on VXLAN GPEencapsulation of a reply packet using the user access information and asame encapsulation manner as for the user access protocol packet.
 15. Apacket encapsulation system comprising: a broadband remote access serveruser plane (BRAS-UP) configured to: receive a user access protocolpacket; obtain user access information corresponding to the user accessprotocol packet; perform virtual extensible local area network genericprotocol extension (VXLAN GPE) encapsulation on the user access protocolpacket and based on the user access information to create anencapsulated user access protocol packet, wherein the encapsulated useraccess protocol packet comprises a VXLAN GPE header and a userinformation header located after and adjacent to the VXLAN GPE header,wherein the VXLAN GPE header comprises an encapsulation protocol fieldwith a preset value, wherein the preset value indicates that theencapsulated user access protocol packet comprises the user informationheader, and wherein the user information header stores the user accessinformation; and send the encapsulated user access protocol packet; anda broadband remote access server control plane (BRAS-CP) configured to:receive the encapsulated user access protocol packet from the BRAS-UP;and decapsulate the encapsulated user access protocol packet to obtainthe user access information and the user access protocol packet, whereinthe user access information comprises user access port information,wherein the user information header comprises a first field, and whereinthe first field comprises the user access port information.
 16. Thepacket encapsulation system of claim 15, wherein the BRAS-CP is furtherconfigured to: perform verification of the user access information;generate a reply packet after the verification; encapsulate the replypacket using the user access information and a same encapsulation manneras for the user access protocol packet to create an encapsulated replypacket; and send the encapsulated reply packet to the BRAS-UP.
 17. Thepacket encapsulation system of claim 15, wherein the user informationheader is 12 or fewer bytes.
 18. The packet encapsulation system ofclaim 15, wherein the user information header is not a network serviceheader (NSH).
 19. The packet encapsulation system of claim 15, whereinthe BRAS-CP comprises a dedicated server.
 20. The packet encapsulationsystem of claim 15, wherein the BRAS-CP comprises a cluster of servers.